1. Field of the Invention
This invention relates to a circular loom, more particularly to a circular loom which has a rod mechanism positioned on an endless raceway assembly of the circular loom so as to prevent removal of shuttles of the circular loom from the raceway assembly.
2. Description of the Related Art
The improvement of this invention is directed to a conventional circular loom 1, as shown in FIGS. 1 and 2. The fundamental weave of the circular loom 1 is to be constituted by means of warp thread (S) and weft thread (N) intersections (see FIG. 4) so as to weave a cloth (see FIG. 2). Then, the cloth 2 passes over a cutting device 3 so as to be cut into the desired size. Finally, with the use of a connecting device 4, the cut cloth 2 is wound into a cylindrical product.
Referring to FIGS. 1 and 3, the weaving principle of the circular loom 1 resides in the application of several shuttles 5 (only one is shown) which slide along an endless raceway assembly 6 of the circular loom 1 so as to drive some weft threads (N). The raceway assembly 6 includes a stationary horizontal upper ring plate 61, a stationary horizontal lower ring plate 62 located under the upper ring plate 61, and a row of circumferentially aligned guide rods 63 interposed between the upper and lower ring plates 61, 62 and spaced apart from each other at a predetermined distance. The shuttle 5, as best shown in FIG. 4, includes a curved shuttle shell 51 disposed vertically between the upper and lower ring plates 61, 62 by means of several wheels 54 (only two can be seen) that are mounted on the upper and lower portions of the shuttle shell 51 and that press against the bottom and top walls of the upper and lower ring plates 61, 62. An elliptical shuttle frame 52 (see FIG. 3) is mounted securely on the inner surface of the shuttle shell 51. A guide bar 53 is secured to an end portion of the shuttle frame 52 (see FIG. 3) at an end thereof. A bobbin 531 is mounted securely on the distal end of the guide bar 53 so as to insert a weft thread (N) into a shed that is formed between the raised and lowered warp threads (S). Two sliding bodies 55 are connected threadably to the outer surface of the shuttle shell 51. Each of the sliding bodies 55 has an outer surface which slides on the guide rods 63.
Referring to FIGS. 3 and 5, the circular loom 1 further includes a rotatable timing disc 7, a power mechanism (not shown) installed in the circular loom 1 and capable of rotating the rotatable timing disc 7, a thrust unit 8 interconnecting the timing disc 7 and one of the end portions of the shuttle frame 52 so as to move the shuttle 5 synchronously with the rotation of the timing disc 7, and a stopper unit 9 interconnecting the timing disc 7 and the other end portion of the shuttle frame 52 and being capable of preventing the shuttle 5 from colliding with another shuttle on the raceway assembly 6.
The main drawbacks of the conventional circular loom 1 are as follows:
1. When the circular loom 1 is in use, the shuttle 5 moves on the raceway assembly 6 by the application of a push force (F) from the thrust unit 8 so that a centrifugal force (A) is produced on the shuttle 5, as shown in FIG. 6. At the same time, the weft thread (N) and the guide bar 53 respectively provide pull forces (B), (C) which are in a direction opposite to that of the centrifugal force (A). Because the resultant force of the pull forces (B), (C) is equal to the centrifugal force (A), the shuttle 5 can slide along the raceway assembly 6 to weave a cloth. However, when it is desired to manufacture a cloth of greater strength, the resultant force of the pull forces (B), (C) should be larger than the centrifugal force (A). Accordingly, the shuttle 5 may be pulled out of the raceway assembly 6. As a result, not only can the circular loom 1 not be operated continuously, but the shuttles 5 and the raceway assembly 6 are also damaged due to collision of the same.
2. When it is desired to manufacture a cloth of weaker strength, the warp thread (S) and the weft thread (N) are thinner. As a result, the warp threads (S) are cut off easily when the wheels 54 of the shuttle 5 press the warp threads (S).